Ball and socket joints of this general type are previously known from West German Registered Design No. 1,815,640. In accordance with this prior known design, the slip liner is injected into the space between the inner and outer rings and then a filler piece is pressed into the slot having a predetermined thickness calculated to produce a predetermined desired radial gap in the bearing. This design presents the disadvantage that it comprises a multiplicity of parts which must be secured by employing specific measures. Furthermore, in the assembly procedure, it is necessary to deform the bore of the outer ring into an oval shape in order to accommodate the filler piece which is pressed in place and this procedure usually results in sacrificing accurate inner ring guidance.
With the foregoing in mind, it is an object of the present invention to provide a method and apparatus for making ball and socket joints of the type generally described which comprises comparatively few parts and which can be produced easily and economically and wherein the bearing play can be adjusted without deforming the outer ring. To this end and in accordance with the method of the present invention, a ring tool is inserted and centered in the bore of the outer ring and thereafter the space between the outer ring and the ring tool is filled by casting or injection with a friction reducing substance, usually a form of plastic. After the plastic sets, the ends of the outer ring are separated which breaks the slip liner at a predetermined break point. The ring tool is then removed and the inner ring of the ball and socket joint is inserted in the bore.
In accordance with another feature of the present invention, annular recesses are formed in the slip liner during the casting or molding or injection process which minimize edge stresses and the danger of fracture are essentially eliminated.
Further, in accordance with the method of the present invention, the amount of play between the inner and outer rings can be selectively controlled by use of an appropriately sized ring tool and preferably an appropriately large ring tool during the injection or casting of the slip liner in the bore of the outer ring.
In accordance with still another feature of the present invention, the apparatus for carrying out the casting process is provided with a blade-like section extending almost over the entire width of the outer ring adjacent the separating line. The separating section projects beyond the lateral surface of the ring tool by a distance corresponding to the thickness of the slip liner. Preferably, the ring tool is made up of a central section and two outer sections attached to the end surfaces wherein the outer diameter of the outer section is larger than the central section and preferably smaller than the inner diameter of the outer ring bore. By this configuration, the slip liner is formed with its ring-shaped free space in the outer region on the side facing the inner ring.